1 /* $OpenBSD: ssh-xmss.c,v 1.14 2022/10/28 00:44:44 djm Exp $*/
3 * Copyright (c) 2017 Stefan-Lukas Gazdag.
4 * Copyright (c) 2017 Markus Friedl.
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 #define SSHKEY_INTERNAL
22 #include <sys/types.h>
34 #include "sshkey-xmss.h"
38 #include "xmss_fast.h"
41 ssh_xmss_cleanup(struct sshkey *k)
43 freezero(k->xmss_pk, sshkey_xmss_pklen(k));
44 freezero(k->xmss_sk, sshkey_xmss_sklen(k));
45 sshkey_xmss_free_state(k);
47 free(k->xmss_filename);
51 k->xmss_filename = NULL;
55 ssh_xmss_equal(const struct sshkey *a, const struct sshkey *b)
57 if (a->xmss_pk == NULL || b->xmss_pk == NULL)
59 if (sshkey_xmss_pklen(a) != sshkey_xmss_pklen(b))
61 if (memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) != 0)
67 ssh_xmss_serialize_public(const struct sshkey *key, struct sshbuf *b,
68 enum sshkey_serialize_rep opts)
72 if (key->xmss_name == NULL || key->xmss_pk == NULL ||
73 sshkey_xmss_pklen(key) == 0)
74 return SSH_ERR_INVALID_ARGUMENT;
75 if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
76 (r = sshbuf_put_string(b, key->xmss_pk,
77 sshkey_xmss_pklen(key))) != 0 ||
78 (r = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0)
85 ssh_xmss_serialize_private(const struct sshkey *key, struct sshbuf *b,
86 enum sshkey_serialize_rep opts)
90 if (key->xmss_name == NULL)
91 return SSH_ERR_INVALID_ARGUMENT;
92 /* Note: can't reuse ssh_xmss_serialize_public because of sk order */
93 if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
94 (r = sshbuf_put_string(b, key->xmss_pk,
95 sshkey_xmss_pklen(key))) != 0 ||
96 (r = sshbuf_put_string(b, key->xmss_sk,
97 sshkey_xmss_sklen(key))) != 0 ||
98 (r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 0)
105 ssh_xmss_copy_public(const struct sshkey *from, struct sshkey *to)
107 int r = SSH_ERR_INTERNAL_ERROR;
111 if ((r = sshkey_xmss_init(to, from->xmss_name)) != 0)
113 if (from->xmss_pk == NULL)
114 return 0; /* XXX SSH_ERR_INTERNAL_ERROR ? */
116 if ((pklen = sshkey_xmss_pklen(from)) == 0 ||
117 sshkey_xmss_pklen(to) != pklen)
118 return SSH_ERR_INTERNAL_ERROR;
119 if ((to->xmss_pk = malloc(pklen)) == NULL)
120 return SSH_ERR_ALLOC_FAIL;
121 memcpy(to->xmss_pk, from->xmss_pk, pklen);
122 /* simulate number of signatures left on pubkey */
123 left = sshkey_xmss_signatures_left(from);
125 sshkey_xmss_enable_maxsign(to, left);
130 ssh_xmss_deserialize_public(const char *ktype, struct sshbuf *b,
134 char *xmss_name = NULL;
136 int ret = SSH_ERR_INTERNAL_ERROR;
138 if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0)
140 if ((ret = sshkey_xmss_init(key, xmss_name)) != 0)
142 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
144 if (len == 0 || len != sshkey_xmss_pklen(key)) {
145 ret = SSH_ERR_INVALID_FORMAT;
150 if (!sshkey_is_cert(key) &&
151 (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0)
162 ssh_xmss_deserialize_private(const char *ktype, struct sshbuf *b,
166 char *xmss_name = NULL;
167 size_t pklen = 0, sklen = 0;
168 u_char *xmss_pk = NULL, *xmss_sk = NULL;
170 /* Note: can't reuse ssh_xmss_deserialize_public because of sk order */
171 if ((r = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0 ||
172 (r = sshbuf_get_string(b, &xmss_pk, &pklen)) != 0 ||
173 (r = sshbuf_get_string(b, &xmss_sk, &sklen)) != 0)
175 if (!sshkey_is_cert(key) &&
176 (r = sshkey_xmss_init(key, xmss_name)) != 0)
178 if (pklen != sshkey_xmss_pklen(key) ||
179 sklen != sshkey_xmss_sklen(key)) {
180 r = SSH_ERR_INVALID_FORMAT;
183 key->xmss_pk = xmss_pk;
184 key->xmss_sk = xmss_sk;
185 xmss_pk = xmss_sk = NULL;
186 /* optional internal state */
187 if ((r = sshkey_xmss_deserialize_state_opt(key, b)) != 0)
193 freezero(xmss_pk, pklen);
194 freezero(xmss_sk, sklen);
199 ssh_xmss_sign(struct sshkey *key,
200 u_char **sigp, size_t *lenp,
201 const u_char *data, size_t datalen,
202 const char *alg, const char *sk_provider, const char *sk_pin, u_int compat)
205 size_t slen = 0, len = 0, required_siglen;
206 unsigned long long smlen;
208 struct sshbuf *b = NULL;
216 sshkey_type_plain(key->type) != KEY_XMSS ||
217 key->xmss_sk == NULL ||
218 sshkey_xmss_params(key) == NULL)
219 return SSH_ERR_INVALID_ARGUMENT;
220 if ((r = sshkey_xmss_siglen(key, &required_siglen)) != 0)
222 if (datalen >= INT_MAX - required_siglen)
223 return SSH_ERR_INVALID_ARGUMENT;
224 smlen = slen = datalen + required_siglen;
225 if ((sig = malloc(slen)) == NULL)
226 return SSH_ERR_ALLOC_FAIL;
227 if ((r = sshkey_xmss_get_state(key, 1)) != 0)
229 if ((ret = xmss_sign(key->xmss_sk, sshkey_xmss_bds_state(key), sig, &smlen,
230 data, datalen, sshkey_xmss_params(key))) != 0 || smlen <= datalen) {
231 r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */
234 /* encode signature */
235 if ((b = sshbuf_new()) == NULL) {
236 r = SSH_ERR_ALLOC_FAIL;
239 if ((r = sshbuf_put_cstring(b, "ssh-xmss@openssh.com")) != 0 ||
240 (r = sshbuf_put_string(b, sig, smlen - datalen)) != 0)
244 if ((*sigp = malloc(len)) == NULL) {
245 r = SSH_ERR_ALLOC_FAIL;
248 memcpy(*sigp, sshbuf_ptr(b), len);
255 if ((ret = sshkey_xmss_update_state(key, 1)) != 0) {
256 /* discard signature since we cannot update the state */
257 if (r == 0 && sigp != NULL && *sigp != NULL) {
258 explicit_bzero(*sigp, len);
275 ssh_xmss_verify(const struct sshkey *key,
276 const u_char *sig, size_t siglen,
277 const u_char *data, size_t dlen, const char *alg, u_int compat,
278 struct sshkey_sig_details **detailsp)
280 struct sshbuf *b = NULL;
282 const u_char *sigblob;
283 u_char *sm = NULL, *m = NULL;
284 size_t len, required_siglen;
285 unsigned long long smlen = 0, mlen = 0;
289 sshkey_type_plain(key->type) != KEY_XMSS ||
290 key->xmss_pk == NULL ||
291 sshkey_xmss_params(key) == NULL ||
292 sig == NULL || siglen == 0)
293 return SSH_ERR_INVALID_ARGUMENT;
294 if ((r = sshkey_xmss_siglen(key, &required_siglen)) != 0)
296 if (dlen >= INT_MAX - required_siglen)
297 return SSH_ERR_INVALID_ARGUMENT;
299 if ((b = sshbuf_from(sig, siglen)) == NULL)
300 return SSH_ERR_ALLOC_FAIL;
301 if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 ||
302 (r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0)
304 if (strcmp("ssh-xmss@openssh.com", ktype) != 0) {
305 r = SSH_ERR_KEY_TYPE_MISMATCH;
308 if (sshbuf_len(b) != 0) {
309 r = SSH_ERR_UNEXPECTED_TRAILING_DATA;
312 if (len != required_siglen) {
313 r = SSH_ERR_INVALID_FORMAT;
316 if (dlen >= SIZE_MAX - len) {
317 r = SSH_ERR_INVALID_ARGUMENT;
322 if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) {
323 r = SSH_ERR_ALLOC_FAIL;
326 memcpy(sm, sigblob, len);
327 memcpy(sm+len, data, dlen);
328 if ((ret = xmss_sign_open(m, &mlen, sm, smlen,
329 key->xmss_pk, sshkey_xmss_params(key))) != 0) {
330 debug2_f("xmss_sign_open failed: %d", ret);
332 if (ret != 0 || mlen != dlen) {
333 r = SSH_ERR_SIGNATURE_INVALID;
336 /* XXX compare 'm' and 'data' ? */
349 static const struct sshkey_impl_funcs sshkey_xmss_funcs = {
352 /* .cleanup = */ ssh_xmss_cleanup,
353 /* .equal = */ ssh_xmss_equal,
354 /* .ssh_serialize_public = */ ssh_xmss_serialize_public,
355 /* .ssh_deserialize_public = */ ssh_xmss_deserialize_public,
356 /* .ssh_serialize_private = */ ssh_xmss_serialize_private,
357 /* .ssh_deserialize_private = */ ssh_xmss_deserialize_private,
358 /* .generate = */ sshkey_xmss_generate_private_key,
359 /* .copy_public = */ ssh_xmss_copy_public,
360 /* .sign = */ ssh_xmss_sign,
361 /* .verify = */ ssh_xmss_verify,
364 const struct sshkey_impl sshkey_xmss_impl = {
365 /* .name = */ "ssh-xmss@openssh.com",
366 /* .shortname = */ "XMSS",
367 /* .sigalg = */ NULL,
368 /* .type = */ KEY_XMSS,
372 /* .keybits = */ 256,
373 /* .funcs = */ &sshkey_xmss_funcs,
376 const struct sshkey_impl sshkey_xmss_cert_impl = {
377 /* .name = */ "ssh-xmss-cert-v01@openssh.com",
378 /* .shortname = */ "XMSS-CERT",
379 /* .sigalg = */ NULL,
380 /* .type = */ KEY_XMSS_CERT,
384 /* .keybits = */ 256,
385 /* .funcs = */ &sshkey_xmss_funcs,
387 #endif /* WITH_XMSS */